If it is coming torwards the front of the trans where it mates up with the motor it can be a rear main seal, or something around tq converter. Have you actually got up under the car? Id try to pinpoint where the wet spot is, take a few pics of that.. Wipe it clean too and see how fast its coming back..

Can also be something more from the top but just happens to be travelling down that route.


Also how often is the car driven and how much at a time? I havent been home that much lately and when I did this past week i had a trans fluid leak on the floor too. Mine looks to be coming from the rear by the trans pan gasket. The car was not driven for 1-2 weeks. Since the first day i started driving it again, i only had a tiny drop the next night, and now its been a few days of driving daily and it stopped.

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2006 X5 4.8is Fully Loaded